1. Filed of the Invention
The present invention relates to hair-care cosmetic compositions having dandruff formation-suppressing effect. More particularly, it relates to hair-care cosmetic compositions containing iodopropynyl butylcarbamate and/or a solution of zinc pyrithione solubilized by a chelator such as N-acyl ethylenediamine triacetate.
2. Description of the Prior Art
In general, "dandruff" is a keratin-like mass resulting from coagulation of dead cells shed from scalp and sebaceous secretion of scalp. Dandruff undergoes a change of its color into reddish gradually and forms a clear boundary from normal skin. Occasionally, it causes a skin disease with accompanying itching and inflammation.
It has been known, though not clearly, that such dandruff may be caused by a hormone imbalance, a nutrition imbalance, nervous stresses, biochemical changes in the epidermal tissue resulting from an excessive multiplication of scalp epidermal cells, growths of microorganisms on the head and activity increase thereof, and inflammations due to air pollutions.
Particularly, Pityrosporum ovlae, which is a parasite on dirty scalp, has been widely recognized as a main cause of dandruff formation. Multiplication and activity increase of this dandruff-causing microorganism make dandruff formation and itches more severe.
Hence, for the hair-care cosmetics for treatment and prevention of dandruff and itching, it is essential to incorporate ingredients capable of suppressing multiplication and activity of the Pityrosporum ovlae effectively and returning abnormal metabolism of the epidermal scalp cells to normal condition.